Move chdir into script itself

chdir for script commands isn't added until ansible 2.4 which we don't
run yet.

Change-Id: I4e042979a7bea3fa87d7cffb12e6728a8357dc9f

playbooks/files/project-requirements-change.py

@@ -100,6 +100,7 @@ def grab_args():
     )
     parser.add_argument('--local', action='store_true',
                         help='check local changes (not yet in git)')
+    parser.add_argument('src_dir', help='directory to process')
     parser.add_argument('branch', nargs='?', default='master',
                         help='target branch for diffs')
     parser.add_argument('--zc', help='what zuul cloner to call')
@@ -149,6 +150,7 @@ def _is_requirement_in_global_reqs(req, global_reqs):
 def main():
     args = grab_args()
     branch = args.branch
+    os.chdir(args.src_dir)
     failed = False
 
     # build a list of requirements from the global list in the

playbooks/requirements-check.yaml

@@ -1,6 +1,4 @@
 - hosts: all
   tasks:
     - name: Run requirements check script
-      script: "files/project-requirements-change.py {{ zuul.branch }}"
-      args:
-        chdir: "{{ zuul.project.src_dir }}"
+      script: "files/project-requirements-change.py {{ zuul.project.src_dir }} {{ zuul.branch }}"